For great movie openings of this or any year, Calvary is a hard one to beat. It’s so simple: Somewhere in Ireland, a priest hears confession from a man who plans to kill him. The reason is revenge for sexual abuse. But this priest isn’t the abuser, who’s already dead. This priest is a decent man. “I’m going to kill you,” says his unseen parishioner, “because you’ve done nothing wrong.” The casting is the coup de grace: Brendan Gleeson, that great soulful hulk, plays the priest. Granted a week to put his affairs in order, he makes his usual parish rounds — a parade of eccentrics, suspects all — and also a personal study of comic and cosmic disillusionment. Gleeson seems like part of the rugged seacoast landscape, and to writer-director John Michael McDonagh he must also seem like a gift from God. The variously affecting subordinate cast includes a somehow desolately radiant Kelly Reilly as the priest’s daughter, and such innately funny actors as Chris O’Dowd and Dylan Moran playing prominently against type, but it’s Gleeson who turns McDonagh’s self-conscious erudition and defense-mechanism irreverence into something transcendent. You’d think fatalistic black comedy and a real quandary of faith wouldn’t be able to coexist. But they do, right from the first commanding moments, in the look on Gleeson’s face.